1. Technical Field
The present invention relates to a voltage controller system for providing stable high voltage bus line voltages using low voltage control signals while minimizing circuit cost and size. More particularly, the present invention relates to a voltage control system for providing a number of high voltages over bus lines to drive capillary channels in a microfluidic system.
2. Related Art
Microfluidic systems are used for the acquisition of chemical and biochemical information. A microfluidic system refers to a device having channels that are generally fabricated at the micron or submicron scale with channel dimensions on the order of 5–100 micrometers. Fabrication of such fluidic microcapillary devices is provided using photolithography and chemical etching processes applied to silicon or glass substrates, techniques typically used in the semiconductor electronics industry. Applications of microfluidic systems include capillary electrophoresis, liquid chromatography, flow injection analysis, and chemical reaction and synthesis.
One method to transport fluids in capillaries of a microfluidic system uses voltages applied across channels in the system to create electric fields, with electrokinetic forces serving to move fluid materials through the channels. Electrokinetic forces have the advantages of direct control, fast response and simplicity.
To control fluid flow in capillaries of a microfluidic system requires a precise voltage to be applied across a number of channels. Microfluidic systems typically use a network of channels in a substrate. The channels connect a number of fluid reservoirs in contact with high voltage electrodes. To move fluid materials through the network of channels, specific voltages are applied to the various electrodes provided in reservoirs at the end of channels.
Voltages applied to the electrodes in the device can be high, for example up to thousands of volts per centimeter. High voltage supplies typically required for each electrode are expensive and bulky. Thus the cost of a complex microfluidic system using electrokinetic forces for fluid movement may be prohibitive.